Lightning-arrester.



No. 863,773. PATENTED AUG. 20, 1907. E. J.BERG.

LIGHTNING ARRESTER.

APPLIOATION IILED mum, 1907.

Witnesses." /r7 ventor': I I EPnstn/TBe/"g, y w; W

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lFNlTED S ATES PAEFE'NT ERNST .l. BERQWI'F SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

LKGHTHING-ARRT: STER.

. Specification of Letters Patent.

Patented Aug. 539, 1907.

To all ZUhOllt it may concern:

Be it known that I, ERNST .T. BERG, a citizen of, the

United States, residing at Schenectady, in the county of Schenectady and State of New York, have invented certain new and useful Improvements in Lightning- Arrestcrs, of which the following isn specification.

My present invention relates to lightning arresters adapted for use on electric systems and more portionlarly direct-current circuits.

It comprises an arrangement of condensers oi ordinaiy type or electrolytic line for relieving the son- I ductors from high frequency oscillations; it also comprises a spark gap sndother elements for relieving the line h'om disturbances of a lower frequency.

The snungement of the apparatus will be understood by reference to the accompshying drawing forming a part of this specification.

The drawing shows my'invention as applied to s direct-current system of shout 600 volts. The line conductor 1 is connected to the translating device 2 through an impedance such as the reuctance coil 3. I have shown the translating device 2 as consisting of a single motor such as a. street car motor; but the drawing is only diagrammatic and the translating device may consist of a group of motors, or as is common, of the entire equipment of'a single car. Two condensers 4 and 5 are placed in series across reactance 3, and have their common armstures connected to ground through a conductor 6. These condensers serve the purpose of permitting a free path for any high irequ'ency-high voltage Oscillations and thereby reduce the potential gradient in the motor winding. This same result is obtained by the reactsnce althoughfor a different reason. The reactance causes a partial re- .iection point for the high voltage usage and therefore reduces the maximum value on the motor winding. Obviously the condenser should contain aslow inductive reactancs as possible and the reactance aslittle capacity between turns as possible. A second path to ground from conductor 1 includes a spark gap 7 with a. blowout magnet 8 arranged so that a direct and heavy discharge of energy may take place from the line conductor to ground without passing through either of the condensers or through reactance 3. I, i g

With the arrangement above described, the relatively infrequent discharges of low frequency pass across sp-gtrl: gaps 7 andthence to ground, while the more common oscillation disturbances induced by switching; short circuits, etc. pass readily through the condensers without breaking down the spark gap 7 end withoutgiving the line current any possible opportunity for following through on the high potential discharge. i

What I claim as new and desire to secure by Letters Patent of the United States, is,

1. A lightning arrestel' comprising a reactance, condensers in parallel therewith, a ground connection for sold condensers, and e separate discharge pathto 'ground through a. spark gap.

2. The combination with slime conductor, a reactsnce connected therewith, condensers in parallel with said re- -sctunce, and a groundedspsrk gap path in parallel with one of said condensers.- I

3. The combination of a line conductor, a translating device electrically connected therewith through a reset once, condensers connected in series across said resctnnce ERNST J. BERG. Witnesses:

Buss-sum B. HULL,

Hams Omen. 

